Dynamo-electric machine.



A. B. FIELD & I. L. GRIFFITH.

DYNAMO ELECTRIC MACHINE. I APPLICATION FILED SEPT- 10, I914- 1,291,459,Patented Jan. 14,1919.

UNITED STATES PATENT OFFICE.

ALLAN B. FIELD, OF MAIBPLE, ENGLAND, AND ISRAEL L. GRIFFITH, OFPITTSBURGH, l PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC ANDMANUFAGT'UBIN COMPANY, A CORPORATION OF PENNSYLVANIA.

DYNAMO-ELECTBIG MACHINE.

Specification of Letters Patent.

Patented Jan. 14, 1919.

To all whom it may concern:

Be it known that we, ALLAN B. FIELD, a subject of the King of GreatBritain, and a resident of Marple, in the count of Cheshire, England,and ISRAEL L RIFFITH, a citizen of the United States, and a resident ofPittsburgh, in the county of Allegheny and State of Pennsylvania, haveinvented,

a new and useful Improvement in Dynamo- Electric Machines, of which thefollowing is a specification.

Our invention relates to ventilating apparatus for dynamo-electricmachines prorided with multiple-layer armature windings, and it has forits object to provide simple and eflicient means for cooling certainparts of alternators and other dynamo-electric machines during theoperation the windings, which temperatures limitthe rating at which themachines may be operated. By a multiple-layer winding, we mean a windingwherein each slot contains a plurality of conductors or coils arrangedin two or more separate layers. Each layer may comprise a conductor orconductors or a portion of a coil or one or more co ls, the respectivelayers being suitably disposed within the slot. a

According to our invention, we provide a ventilating space or ductbetween two layers in each of the armature slots by introducing suitablyinsulated spacers therein in such relation to the several layers thatthey are kept separated from each other Whlle, at the same time, theyare subjectedthroughout their lengths to a cooling medium, such as air.Provision is also made for holding the coils firmly in place within theslots by introducing wedges of insulating material adjacent to the openends of the slots. Further ventilating means is provlded by the use oflongitudinally disposed ducts in the armature teeth.

Figure 1 of the accompanying drawing 15 a sectional view of a portion ofa stator of an alternator provided with a two-layer winding; Fig. 2 is aplan view of a spacer introduced between the coils within a slot; Fig. 3is an enlarged transverse sectional view of the parts contained withinaslot, and Fig. 4 is a fragmentary sectional view of some of the partsshown in Fig. 3.

Referring to the drawing, a stator 1, composed of laminations of sheetmetal in the ordinary manner, is provided with teeth 2 2 and with slots3-3 which are of sufficlent de th to contain two layers of armature conuctors 4 and 5 in spaced relation to each other. The base of each toothis provlded with a longitudinall disposed duct or opening 6. The sides 0each slot are rovided with oppositely disposed grooves located near theinner periphery of the stator. The layers of conductors 4 adjacent tothe open ends of the slots are maintained 1n spaced relation to thelayers 5 at the bottom of the slots by means of the spacers 8.

Wedges 9, driven into the grooves 7 serve to retain the conductorswithin the slots.

The wedges 9 are made of some suitable insulating material, such as hardfiber. The spacer member 8 comprises metal plates 10 and 11 of someconducting material, such as brass, held apart by hard fiber pins 12,shown in Figs. 3 and 1. The pins 12 are cylindrical in form havingextremities 13 of reduced diameter. Holes drilled and counter-sunk inthe metal plates 10 and 11 are adapted to receive the ends 13 of thepins 12 which are placed in sta gered relation to one another throughout1; e length of the plate, as shown in Fig. 2. The pin 14, at the righthand extremity of the spacer member 8, is composed of the same materialas the plates 10 and 11, but is otherwise of the same form as the fiberpins. The outer ends of the pins 12 are upset to form rivet heads,substantially as shown in Fig. 4. This op eration serves to retain theextremities of the pins securely within the holes and to firmly hold theplates in s aced relation to each other, thus forming t e completeddevice.

Insulation of the metal plates is provided by wrappin them with severallayers of some suitab e insulating material, such as fish paper, andcementin the several layers securely to the plate. '1 's insulation isapplied after the plates have been drilled, so

that it is necessary to provide holes in theirisulation coinciding withthose in the plates, in order that the ends of the pins may be receivedwithin the holes. The spacer is grounded by means of a suitablegrounding spring 15 which is composed of some conducting material,preferably phosphor bronze, and is adapted to be retained within a holedrilled in the pin 14, as shown in Fig. 2. The spring bears against oneside of the slot when the s acer 8 is inserted within the slot, thus eectively grounding the spacer to the armature core.

It will be readily understood, from the foregoing description and fromthe drawing, that the conductors are effectively ven- 'tilated, sincethe space between the superposed layers is of relatively large extent inproportion to that taken up by the conductors. The unitary form of thespacers 8 permits them to be located in any portion of the slots withoutany coaction between spacers and grooves in the sides of the slots. Thearrangement of the pins 12 in staggered relation causes the coolingmedium passing through each spacer to take an irregular path that islonger than the armature slot, thereby giving a greater cooling eflect.

The respective layers need not be in superposed relation to each other,as shown in the drawings, for the spacer would be equally effective ifthe layers were oppositely disposed within the slot.

While we have shown our invention in its simplest and preferred form, itis not so limited but is capable of various modifications within thescope of the appended claims. &

We claim as our invention:

1. An armature of a dynamo-electric machine provided with av pluralityof slots, a plurality of layers of current-carrying conductors lying insaid slots, and spacing means between said layers comprising insulatedmetallic plates spaced apart by pins of insulating material.

2. An armature of a dynamo-electric machine provided with a plurality ofslots, a plurality of layers of current-carrying conductors lying insaid slots, and spacing means between said layers comprising insulatedmetallic plates spaced apart by pins of insulating material and meanswhereby said plates are grounded to the armature core.

3. An armature of a dynamo-electric machine provided with a p urality ofslots, a gluraht of layers'of current-carrying conuctors ying in saidslots, and spacing means between said layers comprising insulatedmetallic plates spaced apart by a lurality of ins of insulating materialan electrical y connected but mechanically spaced apart by a pin ofconducting material and means whereby said pin is electrically connectedto the armature core.

4. An armature of a dynamo-electric machine provided with a plurality ofslots, a plurality of layers of current-carrying conductors lying insaid slots, and spacing means between said layers comprising insulatedsteel plates spaced apart by a plurality of pins of insulating materialand electrically connected but mechanically spaced apart by a pin ofconducting material and a spring member mounted on said pin and engagingthe side of said slot to ground the said metal plates to the armaturecore.

5. An armature of a dynamo-electric ma chine provided with a pluralityof slots, a glurahty of layers of current-carrying conuctors lying insaid slots and spacing means between said layers providing an irregularpassage for a cooling medium therebetween, the said means .comprisingspacers composed of insulated metal plates held in spaced relation toone another by fiber pins arranged in staggered relation between theplates for supporting certain of the said layers above the remaininglayers.

In testimony whereof, I have hereunto subscribed my name this 11th dayof August 1914.

ALLAN B. FIELD.

Witnesses:

NORMAN H. SHEARD, -J AS. STEWART Pnoooroo'r.

In testimony whereof, I have hereunto sullrsicribed my name this 31stday of August, 19 i ISRAEL L. GRIFFITH.

Witnesses:

L. O. MoLnna, B. B. Hnms.

